Basket assembly fixture

ABSTRACT

A basket assembly fixture is useful in the construction of a basket assembly for interring spent nuclear fuel rods. The basket assembly fixture has an elongate base and a pair of lifting beams disposed above the base. Lifting beam raising means are provided at both ends of the base to raise the pair of lifting beams. A transverse beam is provided below the two lifting beams and above the base. Transverse beam raising means are provided for raising the transverse beam.

BACKGROUND OF THE INVENTION

[0001] The safe transportation and/or internment of spent nuclear fuelrods is a highly complex task. The spent fuel rods must be rigidlyretained within a structure which virtually guarantees proper spacingbetween the rods. Also, the structure must be extremely rugged and notapt to lose its structural integrity even in a massive traumaticoccurrence, such as in a train derailment.

[0002] One such structure is illustrated in FIG. 1 and will hereinafterbe referred to as a basket assembly. The basket assembly comprises alarge plurality of metal disks, spaced apart by spacers and held rigidlytogether by parallel support rods. Defined within each of the steelplates are square apertures having dimensions which meet rigidtolerances. Each square aperture in each steel plate is carefullyaligned with a square aperture in each of the other steel plates so asto form an elongate, square cross-sectioned tubular opening within thebasket assembly. Thus, the basket assembly has a plurality of suchelongate tubular openings. Spent fuel rods are disposed within elongatetubes having a square external cross section. The elongate tubes aremanufactured to precise tolerances to perfectly fit within each elongatetubular opening within the basket assembly. As illustrated in FIG. 1,the basket assembly is capable of holding a plurality of the elongatetubes, each disposed parallel to the longitudinal axis of the basketassembly.

[0003] The basket assembly illustrated in FIG. 1 meets the rigidstructural integrity requirements set by the industry and the federalgovernment. However, the basket assembly is difficult, time-consumingand tedious to assemble. Because the tolerances between the squareapertures and the elongate tubes are extremely tight, the squareapertures must be aligned with considerable precision. Assembling theplurality of steel plates on the parallel support rods with suchprecision is extremely difficult.

[0004] Traditionally, the basket assembly is assembled vertically. Therearmost steel plate is disposed in the horizontal, threaded onto eachof the parallel support rods. Spacers are placed on each of the parallelsupport rods and then a second steel plate is placed over the parallelsupport rods. The square apertures in the second plate are preciselyaligned with the square apertures in the first plate. In similarfashion, each of the steel plates is assembled onto the parallel supportrods, each steel plate being spaced apart from the next lower steelplate by spacers. Slowly and tediously, the basket assembly is assembledupwardly. As the basket assembly grows taller, scaffolding must beassembled around a basket assembly to allow workers to locate each newsteel plate onto the parallel support rods.

[0005] During the assembly operation, maintaining the square aperturesin the steel plates in near perfect alignment is extremely difficult. Itis frequently necessary to disassemble a partially assembled basketassembly and begin the process of assembling the basket assembly anew.

[0006] Accordingly, there is a need for a method for assembling basketassemblies which avoids these aforementioned problems with the priorart.

DRAWINGS

[0007] These features, aspects and advantages of the present inventionwill become better understood with regard to the following description,appended claims and accompanying figures where:

[0008]FIG. 1 is an isometric view of a basket assembly which is thesubject of the present invention;

[0009]FIG. 2 is an isometric view of a basket assembly fixture havingfeatures of the invention;

[0010]FIG. 3 is a side view of the basket assembly fixture illustratedin FIG. 2, showing support disks disposed in place upon the fixture;

[0011]FIG. 4 is a diagrammatic side view of the basket assembly fixtureillustrated in FIG. 3 showing one step in the assembly of a basketfixture;

[0012]FIG. 5 is a diagrammatic side view of the basket assembly fixtureillustrated in FIG. 3 showing another step in the assembly of a basketfixture;

[0013]FIG. 6 is a diagrammatic side view of the basket assembly fixtureillustrated in FIG. 3 showing another step in the assembly of a basketfixture; and

[0014]FIG. 7 is a diagrammatic side view of the basket assembly fixtureillustrated in FIG. 3 showing another step in the assembly of a basketfixture.

DETAILED DESCRIPTION

[0015] The following discussion describes in detail one embodiment ofthe invention and several variations of that embodiment. This discussionshould not be construed, however, as limiting the invention to thoseparticular embodiments. Practitioners skilled in the art will recognizenumerous other embodiments as well.

[0016] The invention is a basket assembly fixture 10 useful in theconstruction of a basket assembly 1 for interring spent nuclear fuelrods. As noted in the Background Section, such a basket assembly 1 isillustrated in FIG. 1. The basket assembly 1 comprises a plurality ofspaced apart steel support disks 2 assembled in parallel in spaced apartfashion by spacers 3 and held together by parallel support rods 4. Thebasket assembly defines a plurality of elongate tubular openings havingsquare cross-sections. Each elongate tubular opening is capable ofaccepting and retaining an elongated tube 5 having a squarecross-section.

[0017] In the invention, the basket assembly fixture 10 comprises anelongate base 12, a pair of lifting beams 14 disposed above the base 12and a transverse beam 16 disposed above the base 12 but below thelifting beams 14.

[0018] As illustrated in FIG. 2, the base 12 can have a rectangularshaped perimeter 18. The rectangular perimeter 18 can be reenforced by aplurality of spaced apart frame transverse beams 20.

[0019] Disposed at each of the two ends 21 of the base 12 are endstanchions 22. Each end stanchion 22 comprises a pair of verticalstanchion support posts 24. Each of the stanchion support posts 24 canbe reenforced by a stanchion angular member 26. A horizontal stanchionbeam 28 is disposed between the stanchion support posts 24. In theembodiment illustrated in the drawings, the horizontal stanchion beam 28is a hollow box beam having a flat horizontal upper surface 30.

[0020] Also disposed at each end 21 of the base 12 are a pair ofvertical plate support structures 32.

[0021] The base 12 further comprises a pair of longitudinal platesupport rails 34 disposed in parallel to the longitudinal axis 36 of thebase 12.

[0022] The entirety of the base 12 is made from heavy duty materials,such as from steel beams.

[0023] The pair of lifting beams 14 are disposed parallel to thelongitudinal axis 36 of the base 12. Each of the pair of lifting beams14 is supported at its respective opposite ends by the pair ofhorizontal stanchion beams 28. The pair of lifting beams 14 aretypically steel box beams having flat horizontal upper surfaces 40 andlower surfaces 42 (see FIG. 4).

[0024] The basket assembly fixture 10 further comprises lifting beamraising means 44 for alternatively raising and lowering both ends ofeach lifting beam 14. In the embodiment illustrated in the drawings, thelifting beam raising means 44 are provided by hydraulic jacks 46, onedisposed beneath each end of each lifting beam 14. Each jack 46 operatesvia holes (not shown) drilled within one of the horizontal stanchionbeams 28. In one embodiment, each jack 46 operates against a slidablepin (not shown) which is vertically disposed within one of the holes inone of the horizontal stanchion beams 28.

[0025] The basket assembly fixture 10 further comprises lifting beamlateral shifting means 48 for laterally shifting both ends of eachlifting beam 14. In the embodiment illustrated in the drawings, thelifting beam shifting means 48 are provided by horizontally disposedhydraulic jacks 50 disposed within each of the ends of each of thehorizontal stanchion beams 28. In the embodiment illustrated in thedrawings, the horizontally disposed jacks 50 operate against push plates52 which slide within slots 54 disposed within the upper surface 30 ofthe horizontal stanchion beam 28.

[0026] The transverse beam 16 is disposed generally horizontally abovethe frame 12 and directly below, and generally perpendicular to, the twolifting beams 14. The transverse beam 16 has opposed ends, each of whichis supported on a transverse beam support structure 56 which can beattached to one of the sides of the perimeter 18 of the base 12.

[0027] The basket assembly fixture 10 further comprises transverse beamlifting means 58 for alternatively raising and lowering both ends of thetransverse beam 16. In the embodiment illustrated in the drawings, thetransverse beam raising means 58 are provided by a pair of verticallydisposed hydraulic jacks 60.

[0028] Typically, the basket assembly fixture 10 further comprisesalignment measuring means 62 for aligning the horizontal and verticaldisposition of both of the pairs of lifting beams 14 (see FIG. 7). Inthe embodiment illustrated in the drawings, the alignment measuringmeans 62 comprises a pair of tight wire assemblies 64. Each tight wireassembly 64 comprises (i) a length of wire 66 disposed above the base 12and parallel to the longitudinal axis 36 of the base 12, and (ii)tightening means 68 for drawing the length of wire 66 taut. In theembodiment illustrated in the drawings, each tight wire assembly 64comprises a length of wire 66 drawn taut between a pair of opposedvertical tight wire support posts 70. Each vertical tight wire supportpost 70 comprises a rotatable sheave 72 to minimize damage to eachlength of wire 66. The tightening means 68 are provided by a pair ofweights 74, each disposed at one end of each length of wire 66. Eachsuch weight 74 is capable of drawing each length of wire 66 taut suchthat each length of wire 66 is nearly perfectly linear. In a typicalembodiment, each length of wire 66 is made from a length of 0.035 inchessteel wire and the weight of each weight 74 is about 30 pounds. Theheight and the placement of the vertical tight wire support posts 70 arecarefully determined so that a length of wire 66 drawn between opposingsheaves 72 is nearly perfectly horizontal and nearly perfectly parallelto the longitudinal axis 36 of the base 12.

[0029] The method of assembling a basket assembly 1, such as illustratedin FIG. 1 using the basket assembly fixture illustrated in FIG. 2, isbest seen with regard to FIGS. 3-7. FIG. 3 illustrates the initial stepsof the method wherein the pair of lifting beams 14 are removed from thebasket assembly fixture 10 and the plurality of basket assembly supportdisks 2 are disposed vertically, spaced apart from one another, onto thepair of longitudinal plate support rails 34. The first of the basketassembly support disks 2 is disposed in abutment or in near abutment toone of the two vertical plate support structures 32, while the last ofthe basket assembly support disks 2 is disposed in abutment or in nearabutment with the other of the vertical plate support structures 32.

[0030] Once the plurality of basket assembly support disks 2 aredisposed on the longitudinal plate support rails 34, each of the supportrods 4 is threaded through appropriate support rod apertures in eachbasket assembly support disk 2. As the threading of the support rods 4is accomplished, appropriate spacers 3 are disposed along the supportrods 4 in between each pair of adjoining basket assembly support disks2. As illustrated in FIG. 3, the nuts 6 at the ends of the support rods4 are not tightened down at this point in the method.

[0031] After the plurality of basket assembly support disks 2 isarranged as illustrated in FIG. 3, the pair of lifting beams 14 arethreaded through appropriate lifting beam apertures 76 in each of thesupport disks 2 as illustrated in FIG. 4. The upper edge of each of thelifting beam apertures 76 in each of the basket assembly support disks 2is horizontal.

[0032] After the lifting beams 14 are installed as illustrated in FIG.4, the lifting beams 14 are raised by the lifting beam raising means 44as illustrated in FIG. 5. The lifting beams 14 are raised sufficientlyto raise each of the basket assembly support disks 2 above the base 12of the basket assembly fixture 10. Because of the excessive weight ofthe basket assembly support disks 2, both lifting beams 14 tend to sagslightly at their centers.

[0033] The next step is illustrated in FIG. 6 wherein the sag in each ofthe lifting beams 14 is taken out by raising the transverse beam 16using the transverse beam raising means 58.

[0034] Next, each of the support disks 2 is vertically aligned using thealignment measuring means, the lifting beam raising means 44 and thetransverse beam raising means 58. In embodiments wherein the verticalalignment measuring means 62 comprises a pair of tight wire assemblies64, the vertical alignment of each of the support disks 2 is compared tothe horizontally disposed length of wire 66 (see FIG. 7). To the extentthat vertical adjustment is required, such adjustment can beaccomplished by raising or lowering the lifting beam raising means 44and/or the transverse beam raising means 58.

[0035] Similarly, the lateral alignment of the plurality of supportdisks 2 is accomplished using the alignment measuring means 62 and thelifting beam lateral shifting means 48. Where the lateral alignmentmeasuring means 62 is provided by a tight wire assembly 64, the lateralalignment of each support disk 2 is aligned with the length of wire 66(again, see FIG. 7). To the extent that adjustment is necessary, suchadjustment can be accomplished using the lifting beam lateral shiftingmeans 48 to shift the lifting beams 14 either to one side or to theother.

[0036] Once the plurality of support disks 2 are perfectly alignedvertically and laterally, the support disks 2 are rigidly attached toone another. In the embodiment illustrated in the drawings, this isaccomplished by tightening down the nuts 6 on the ends of each of thesupport rods 4. Once this is accomplished, the basket assembly 1 is bothrigid and perfectly aligned, ready to accept a plurality of elongatetubes 5 containing spent nuclear fuel rods (as illustrated in FIG. 1).

[0037] Having thus described the invention, it should be apparent thatnumerous structural modifications and adaptations may be resorted towithout departing from the scope and fair meaning of the instantinvention as set forth hereinabove and as described hereinbelow by theclaims.

What is claimed is:
 1. A basket assembly fixture useful in theconstruction of a basket assembly for interring spent nuclear fuel rods,the basket assembly fixture comprising: (a) an elongate base having afirst end, an opposed second end and a longitudinal axis; (b) a pair oflifting beams disposed above the base and generally parallel to thelongitudinal axis of the base, each lifting beam having a first end andan opposed second end; (c) lifting beam raising means for alternativelyraising and lowering both ends of each lifting beam; (d) lifting beamlateral shifting means for laterally shifting both ends of each liftingbeam; (e) a transverse beam disposed generally horizontally above theframe, the transverse beam also being disposed below and generallyperpendicular to the two lifting beams, the transverse beam having afirst end and an opposed second end; and (f) transverse beam raisingmeans for alternatively raising and lowering both ends of the transversebeam.
 2. The basket assembly fixture of claim 1 further comprisingalignment measuring means for aligning the horizontal and verticaldisposition of both of the pair of lifting beams.
 3. The basket assemblyfixture of claim 2 wherein the alignment measuring means comprises apair of tight wire assemblies, each tight wire assembly comprising (i) alength of wire disposed above the base and generally parallel to thelongitudinal axis of the base and (ii) tightening means for drawing thelength of wire taut.
 4. The basket assembly fixture of claim 3 whereinthe tightening means comprises at least one weight disposed at the endof the length of wire.
 5. The basket assembly fixture of claim 1 whereinthe lifting beam raising means, the lifting beam lateral shifting meansand the transverse beam raising means are hydraulic jacks.
 6. The basketassembly fixture of claim 1 further comprising a plurality of basketassembly support disks supported on the frame and disposed in verticalplanes and in parallel with one another, each basket assembly supportdisk comprising at least two support beam apertures therethrough, eachof the two lifting beams being disposed through support beam apertures.7. The basket assembly fixture of claim 6 wherein the plurality ofbasket assembly support disks are fastened to one another by a pluralityof generally parallel support rods.
 8. A method of preparing a basketassembly for interring spent nuclear fuel rods, the basket assemblycomprising a plurality of support disks disposed parallel to one anotherand spaced apart from one another, the support disks all having at leasttwo lifting beam apertures disposed therethrough, the method comprisingthe steps of: (a) disposing a plurality of basket assembly support diskson a basket assembly fixture comprising: (i) an elongate base having afirst end, an opposed second end and a longitudinal axis; (ii) a pair oflifting beams disposed above the base and generally parallel to thelongitudinal axis of the base, each lifting beam having a first end andan opposed second end; (iii) lifting beam raising means foralternatively raising and lowering both ends of each lifting beam; (iv)lifting beam lateral shifting means for laterally shifting both ends ofeach lifting beam; (v) a transverse beam disposed generally horizontallyabove the frame, the transverse beam also being disposed below andgenerally perpendicular to the two lifting beams, the transverse beamhaving a first end and an opposed second end; and (vi) transverse beamraising means for alternatively raising and lowering both ends of thetransverse beam; the plurality of basket assembly support disks beingdisposed in vertical planes within the frame of the basket assemblyfixture with each of the pair of lifting beams being disposed generallyhorizontally through one of the lifting beam apertures in each of thesupport disks; (b) lifting the plurality of support disks away from theframe of the basket assembly fixture by raising the lifting beams usingthe lifting beam raising means; (c) vertically aligning the plurality ofsupport disks using vertical alignment measuring means, the lifting beamraising means and the transverse beam raising means; (d) laterallyaligning the plurality of support disks using lateral alignmentmeasuring means and the lifting beam shifting means; (e) thereafterrigidly attaching the plurality of support disks to one another to formthe basket assembly; and (f) thereafter removing the pair of liftingbeams from the basket assembly and removing the basket assembly from thebasket assembly fixture.
 9. The method of claim 8 wherein the verticalalignment measuring means and the lateral alignment measuring means areprovided by a pair of tight wire assemblies, each tire wire assemblycomprising (i) a length of wire disposed above the base and generallyparallel to the longitudinal axis of the base, and (ii) tightening meansfor drawing the length of wire taut.
 10. The method of claim 9 whereinthe tightening means comprises at least one weight disposed at the endof the length of wire.
 11. The method of claim 8 wherein the pluralityof basket assembly support disks are fastened to one another by aplurality of generally parallel support rods.
 12. The method of claim 8wherein the plurality of basket assembly support disks are fastened toone another by a plurality of parallel support rods and are spaced apartfrom one another by spacer sleeves disposed on the support rods.
 13. Thebasket assembly fixture of claim 8 wherein the lifting beam raisingmeans, the lifting beam lateral shifting means and the transverse beamraising means are hydraulic jacks.